Elements, Compounds and Mixtures Flashcards
Are covalent bonds really strong or really weak?
Really strong
Are ionic bonds really strong or really weak?
Really strong
Can graphene conduct electricity?
yes
Can you see nanoparticles with a light microscope?
No, they are too small
Do metals have a high melting point?
Yes
Do simple covalent substances need a high or low temperature to melt/boil?
Low temperature
Does graphite have a high or low melting point?
High due to strong covalent bonds
Give 2 properties of ionic compounds
High melting and Boiling point
Conduct electricity when melted or dissolved
Give 3 examples of Giant Covalent Structures.
Silicon Dioxide
Diamond
Graphite
Give 3 types of substances covalent bonding can make.
Simple molecular substances
Polymers
Giant Covalent Structures
How are anions formed?
When non-metals react with a metal to achieve a full outer shell, giving them a negative charge.
How are the atoms arranged in graphite?
They are arranged in hexagonal flat sheets, which form layers over one another
How can you model the ions in an ionic compound?
with the dot and cross diagram.
How do covalent bonds work?
Electrons are shared between atoms, so each gains electrons.
How do ionic compounds form?
when a metal reacts with a non-metal, electrons are transferred from the outer shell of the metal to the non-metal. This makes the non-metal an anion and the metal a cation.
How do you conduct crystallisation?
1) place solution into evaporation dish
2) heat with water bath
3) once you start seeing some crystals forming after some of the solvent has evaporated, stop heating and leave to cool
4) when it cools more crystals should form
5) then conduct filteration to filter out the crystals
How do you work out moles?
mass/ mr
How does ionic bonding work?
Electrons are transferred from one atom to another, creating to ions of opposite charges. They attract due to their opposite charges and form an ionic bond.
How does metallic bonding work?
The atoms give up the electrons in their outermost shell and become cations. The electrostatic forces between the neg. electrons and pos. ions, hold everything together.
How does paper chromatography separate substances?
a solution with multiples substances is put onto the baseline and the paper is put in a solvent which is under the baseline. As the solvent travels up, the solution dissolves in the solvent and travels up. The more soluble substances in the solution travel further up the mobile phase than the less soluble ones
How does simple distillation work?
The solution is heated, and the liquid evaporates. The evaporated liquid passes through a tube with a water jacket around it. The water jacket has continuous cold water coming in from the bottom and exiting from the top. The water jacket condenses the evaporated liquid and it falls into a beaker
How does the apparatus look for simple distillation?
a circular flask with a cork with a temperature which a tube extending from the neck. A water jacket around the extended tube (condenser).
How is a cation formed?
when metals react, they lose their outer shell electrons, giving them a positive charge
How many carbon atoms are each carbon atom bonded to in graphite?
3 others
How many carbon atoms does buckminsterfullerene have?
60
How many electrons can the first shell hold?
2
How many electrons can the third shell hold?
8
How many other carbon atoms is one carbon atom bonded to in diamond?
4 other carbon atoms
What 2 elements is steel usually made from?
Mostly iron, and some carbon
What are 2 alloptropes of carbon?
Diamond and Grpahite
What are 2 properties of giant covalent structures?
Very strong
High melting/boiling point
What are 2 features of the fractionating column?
it is full of glass rods
cooler at the top than at the bottom
What are 2 ways to separate a solution?
evaporation and crystallisation
What are 4 examples of formulations?
fuels, cleaning agents, paint, medicines, alloys, fertilisers
What are formulations?
mixtures that have been prepared using a specific formula
What are fullerenes?
Graphene bent into tubes or spheres